The masculine noun אפריון ('appiryon), of unclear meaning. It occurs only once as well, in the Song of Solomon 3:9, where Solomon makes some kind of chair. The kind is described by our word, and it's possibly some kind of recliner, a bed-like lounger.

In ancient Israel, people would indicate their state of mourning by wrapping themselves in sackcloth and covering themselves with ashes. Our two roots are obviously related.